Tailoring physical properties of monoglycerides oleogels using high-intensity ultrasound

The effects of high-intensity ultrasound application (HIU-20 kHz, 96 W, 3 pulses: 10 s on/5s off) and cooling rate (0.1 and 10 °C/min) on physical properties of monoglycerides (MG) oleogels (3, 4.5, and 6 wt%) were evaluated. Oleogels melting profile, rheological and textural properties, crystal microstructure, crystal length (L_c), polymorphic behavior, oil binding capacity (OBC), and solid fat content (SFC) were determined after 24 h of storage at 5 or 25 °C. HIU caused significant changes in the MG crystallization behavior, producing a decrease in L_c and a stronger and more elastic network with higher OBC. HIU increased the adhesiveness of all samples whereas did not affect their cohesiveness. The effects of HIU application were enhanced by cooling at 0.1 °C/min and storing at 5 °C. Neither SFC nor thermal behavior were affected by HIU and the desired β' polymorphism was obtained in all oleogels. This study shows that physical properties of MG oleogels can be significantly improved by HIU application to obtain suitable fats with low level of saturated fatty acids for food applications.